Method and system of monitoring respiratory signal by radio

Abstract

A method and system is provided for monitoring a respiratory signal by radio. The method includes the steps of converting a change in electric resistance, which is caused by a change in abdominal circumference measured through a rubber waistband that is made of conductive rubber and is mounted on a lower garment of a testee during respiration, into a voltage signal, performing A/D conversion on the voltage signal, and transmitting the converted digital signal a short distance by radio using a wireless communication protocol for ZigBee, and receiving the respiratory signal transmitted by radio, transmitting it to a computer unit by wire through an RS-232 port that is a serial communication port, and enabling a tester to monitor the respiratory signal through a screen.

1 . A system of monitoring a respiratory signal by radio, the system comprising:
 a connector that is connected to opposite ends of a rubber waistband, the rubber waistband being mounted on a lower garment of a testee and being made of rubber including conductive particles;   a radio transmitter that is electrically connected with the connector, converts a change in electric resistance, which is caused by a change in abdominal circumference measured through the rubber waistband during respiration, into a voltage signal, performs analog/digital (A/D) conversion on the voltage signal, and transmits the converted digital signal to a short distance by radio using a wireless communication protocol for ZigBee; and   a radio receiver that receives the respiratory signal, transmitted by radio using the ZigBee wireless communication protocol, through a reception antenna, converts the respiratory signal into serial information, and outputs the converted serial information through a RS-232 port,   wherein the respiratory signal is monitored by calculating the input respiratory signal and checkup parameters at the radio receiver, and outputting the calculated result to a monitor screen.   
     
     
         2 . The system as claimed in  claim 1 , wherein the radio transmitter comprises:
 a Wheatstone bridge circuit, one resistor of which operates the rubber waistband to convert a change in electric resistance of the rubber waistband into a voltage signal;   a differential amplifier circuit that amplifies and outputs a difference between the voltage signals output from the Weston bridge circuit to one voltage signal;   a low-pass filter circuit that extracts a voltage signal corresponding to the respiratory signal, from which high-band noise is minimized by allowing only a low-band signal to pass therethrough, from the voltage signal amplified through the differential amplifier;   an analog/digital (A/D) converter circuit that converts the respiratory signal output from the low-pass filter circuit into a digital signal; and   a ZigBee transmission circuit that transmits the digital signal output from the A/D converter circuit through a reception antenna by radio to a short distance using a ZigBee wireless communication protocol.   
     
     
         3 . The system as claimed in  claim 1 , wherein the radio transmitter is carried in a pocket of a lower or upper garment of the testee. 
     
     
         4 . The system as claimed in  claim 1 , wherein the A/D converter circuit and ZigBee transmission circuit of the radio transmitter make use of a semiconductor ship.